An investigation has found a number of suspicious 'fake' mobile phone towers in London that could form part of the Stingray mass phone surveillance system first uncovered last year.
A report on Sky News said that they are made to look like normal mobile phone towers but actually have a more sinister purpose. Rather than provide mobile services, the towers use International Mobile Subscriber Identity (IMSI) 'catchers' to gather information, according to the report.
Sky said that it has found at least 20 of the towers across London, and has spoken to privacy and rights experts about the discovery.
Eric King, deputy director of Privacy International, and a dogged opponent of snooping practices, told Sky News that IMSI systems are not precise and lead to bulk collection.
"With IMSI catchers, it's very difficult for them to be used in a targeted manner. In an urban space, thousands of people's mobile phones would be swept up in that dragnet. What they do with that data, we don't know," he said.
"We know police have been using them for years, but this is the first time that it's been shown that they're being deployed in the UK."
Sky used kit from a German company called GMSK Cryptophone to sniff out the IMSI towers over a three-week period.
"The abnormal events that Sky News had encountered can clearly be categorised as strong indicators for the presence of IMSI catchers in multiple locations," said GMSK.
However, it is not clear who has placed the IMSI catchers in London or their purpose. Sky added that reports last year claimed that the Metropolitan Police were using the system, but this came from anonymous sources and it is not something that the police have confirmed.
The Metropolitan Police has, however, a strong commitment to the adoption of technology, and recently announced plans to equip 20,000 officers with body-worn cameras.
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